Effect of speed ratio in edge routing of carbon fiber-reinforced plastics by rotary ultrasonic elliptical machining

Edge routing carbon fiber-reinforced plastic structures is the first and mandatory operation after demolding. In order to solve the problems such as tool clogging and mechanical damages at the machined surface in edge routing of carbon fiber-reinforced plastics by grinding tools, the rotary ultrasonic elliptical machining technique was used in edge routing carbon fiber-reinforced plastics for the first time. First, the rotary ultrasonic elliptical machining principle and an analysis of the effect of the speed ratio, R_s (i.e., the ratio of the nominal cutting speed to the maximum tool vibration speed in the cutting direction), on the relative motion of the tool and workpiece were presented as the speed ratio greatly influences the rotary ultrasonic elliptical machining performance. Then, the edge routing experiments by rotary ultrasonic elliptical machining were conducted to study the machining quality at different speed ratios. The results showed that the grinding forces at R_s 0.1 decreased about 19% (normal grinding force) and 17% (tangential grinding force) than that at R_s 0.8 after cutting 100min. The tool diameter reduction at R_s 0.1 was 34% lower than that at R_s 0.8 after cutting 100min and the machined surface integrity at R_s 0.1 was also modified at the end of the experiments. The experimental findings suggest that the optimal integrated surface could be achieved by applying the rotary ultrasonic elliptical machining method with the fine size diamond grinding tool and the low speed ratio.